Johnson Wagner, the 2008 Shell Houston Open champion, already has five top-15 finishes in 2012, including a victory at the Sony Open.

Chris Duncan

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HUMBLE, Texas

Johnson Wagner’s first PGA Tour victory proved to be more of an anomaly than a springboard.

Wagner won the 2008 Shell Houston Open, then failed to earn a top-10 finish the rest of the year, missing five cuts. The following year was even worse, with 13 missed cuts in 27 starts.

“I went into a little dark place in my golf career,” Wagner said.

He and his wife, Katie, had two children in the midst of his slump, and Wagner said fatherhood took him away -- happily -- from concentrating on his game.

Wagner re-dedicated himself last year with a new personal trainer and emphasis on his short game. The hard work has yielded eye-popping results this year, and Wagner returns to Houston this week with five top-15 finishes in 2012, including a victory at the Sony Open.

Phil Mickelson is the defending champion at the Houston Open, and the field also includes local favorite Fred Couples and international stars Lee Westwood, Padraig Harrington, Graeme McDowell and Ernie Els, who must win to avoid missing the Masters for the first time since 1993.

Wagner is not a household name, but he’s the player atop the FedExCup standings and he leads the tour in birdies (138) and eagles (8).

“It’s nice to see stuff pay off so quickly in the year,” he said, “and I’ve set myself up for some big goals for the rest of the year.”

And he’s working on becoming more recognizable to casual fans, still sporting a shaggy black mustache that he started growing before the season began. It’s drawn so much attention, he’s thinking about turning it into his trademark.

“It’s incredible,” Wagner said. “It’s kind of given me my own little brand, I guess. Thought if I played well, it would give me a little more recognition. It’s kind of been unbelievable.”

The tournament became the run-up event to the Masters in 2007, and organizers have embraced the distinction. The Tournament Course at Redstone is manicured to simulate conditions at Augusta, with light rough, fairways mowed toward the tees, shaved mounds around the greens and slick greens.

The setup has generated mostly positive feedback among the pros, particularly among international players. This year, the field has 40 players representing 17 countries outside of the United States, both tournament records.

Els is approaching the tournament like any other, and not worrying about the bigger prize at stake. He’ll consider winning at Redstone a bonus, and is more focused on building on his strong start this year, which includes top-five finishes in his past two starts.

“You can’t go into a week putting pressure on yourself to win to get into another week,” Els said Wednesday. “If I get into the Masters, that’s great. If I don’t, then I’ve had many Masters that I can look back at, and I’ll get back in there next year.”

The Masters could still offer a special invitation to Els, like tournament officials did for Greg Norman in 2002. Ryo Ishikawa, a nine-time winner on the Japan Golf Tour, has a special invitation this year.

Els isn’t expecting a call between now and Sunday, when the Masters field will be set.

“It is an invitational event,” he said, “and they have their reasons to invite somebody or not, and that’s the sad part. I’ll probably miss it for the first time in 18 or 19 years. My streak will come to an end, unfortunately.”

Mickelson, meanwhile, played at Augusta on Monday and Tuesday before arriving in Houston late Wednesday. He’ll play the first two rounds with defending Masters champion Charl Schwartzel and Couples, who played at the University of Houston and draws immense galleries here every year.

Shell has been the tournament’s title sponsor since 1992, the third-longest tenure on tour. The oil company’s current contract runs through 2017.